When looking at steel-string guitars for the first time, it can look like a jungle of letters and numbers. But there is a system to it. Here you will get an overview of the classic body sizes and how they sound.
Generally, a larger and deeper body and a longer scale length provide more volume and more bass. However, the wood types also have a major impact on the tone, so use the guidelines below as a starting point.
The designations originate from C.F. Martin, but are used by many other manufacturers, including Sigma.
Dreadnought (D)
The dreadnought is probably the best-known guitar size and the shape most people associate with an acoustic guitar. Martin made the first dreadnoughts in the 1930s and named them after the largest class of warships at the time, because the guitar was larger and more powerful than anything else on the market.
Since then, almost every guitar manufacturer has made their own dreadnoughts, and Martin's D-models such as the D-18, D-28, HD-28, and D-35 are still the ones that others are measured against.
The dreadnought is an all-round guitar that can handle big chords, fingerstyle, and bluegrass. Bob Dylan, Johnny Cash, and Van Morrison are among the many who have used it.
Jumbo (J)
Like the dreadnought, the jumbo was developed to provide more volume at a time when orchestras were getting larger. The body has wider "hips" and a narrower "waist" than a dreadnought. This gives a tone that is big and powerful, but with slightly less fullness in the bass. Martin's J-40 is particularly associated with Neil Young.
0, 00, and 000
The jumbo's proportions are related to the 0, 00, and 000 body sizes. They all have a narrow waist, and 0 is the smallest, 00 the next smallest, and 000 the largest.
With a smaller body comes less volume, but in return you get refinement and balance between the bass and treble. The bass never takes over, so the details in the high registers stand out clearly, even when you strike hard. That is why they are widely used for blues, ragtime, and fingerstyle, where the guitar often plays the bass and melody at the same time.
On 0 guitars, the body and neck always meet at the 12th fret, while the 00 and 000 can have both the 12th and 14th frets free from the body. Martin's 000-28EC Eric Clapton is a well-known example of a 000. 0 and 00 are often chosen by guitarists who want to capture the sound of the blues masters from the 1920s and 1930s.
OM (Orchestra Model)
The OM is a further development of the 000. The body is the same size, but the fretboard is wider and the scale length slightly longer. This gives a fuller tone and a little more room for the fingers. Paul Simon has recorded many of his greatest songs on a Martin OM-42.
M
The logical continuation of the zeros would be 0000, but Martin called the size M. Seen from the front, the body has the same proportions as a jumbo, but it is thinner and therefore related to the 0 models. Martin M-38 is associated with Tom Paxton, among others. If you want to read a story about an M38, read When Ralph McTell Borrowed Ole's M38.
Grand Performance (GP)
The GP is a newer Martin size that sits between the large models (dreadnought and jumbo) and the medium-sized models (OM and 000). It approaches the large models in volume without the bass becoming dominant, and it is good for fingerstyle. If a dreadnought feels too big to sit with, and you think the smaller models sound too thin, a GP may be the solution.
SC
The SC is Martin's newest body shape in the Road Series, with a cutaway and a neck that makes the high frets easy to reach. It is made for guitarists who play a lot up the neck, such as the Martin SC-13E Koa.
Which size should I choose?
- Chords for singing and all-round playing: dreadnought or jumbo.
- Fingerstyle, blues, and a guitar that is comfortable to sit with: 0, 00, 000, or OM.
- Both fingerstyle and volume: GP or M.
The best advice is to try several sizes. Stop by Aarhus or Copenhagen, or see all acoustic guitars. If you need your first guitar, read The Hunt for the First Guitar.